Live Communications Server is Microsoft's answer to corporate instant messaging. It integrates presence information into Exchange for display in Outlook and SharePoint server. (Microsoft is trying to move away from the Public Folder model and to 'group stuff goes on SharePoint' model).

Often the Exchange admin gets tasked with implementation. LCS itself isn't all that hard but it joins several elements into one pile of considerations. IM, Interaction with Telephony systems, Public IM, Presence information... Microsoft isn't really joking when they tell people it will change the way you do business.

In all that mix, I recently got to implement Public IM. The documentation is, well, confusing. Part of that is because you have to sort through the various scenarios and versions to find something you understand. I had downloaded the Live Communications Server Resource Kit early on.

LCS Diag is easy enough to figure out and first to use. Less obvious though is the SIP View tool. When you enable logging to troubleshoot issue's, the log file format is XML. It's all there but linear and unformatted. So, open up SIP View and drop in the log file and you get a nicely formatted log that's much easier to read through.

LCSPing is another great tool. It can help you determine if the ports you need LCS to work with are open. Rather then trying to telnet to port 5061 of the server, you can run the tool.

and find out if you have connectivity. If you get nothing, then investigate if your network has it's outgoing ports on 5061 locked down.

I wish I'd known about these two tools much earlier in the process, but better late then never.